As the most important skeletal component in plants, the polysaccharide cellulose is an almost inexhaustible polymeric raw material with fascinating structure and properties. Formed by the repeated connection of D-glucose building blocks, the highly functionalized, linear stiff-chain homopolymer is characterized by its hydrophilicity, chirality, biodegradability, broad chemical modifying capacity, and its formation of versatile semicrystalline fiber morphologies. In view of the considerable increase in interdisciplinary cellulose research and product development over the past decade worldwide, this paper assembles the current knowledge in the structure and chemistry of cellulose, and in the development of innovative cellulose esters and ethers for coatings, films, membranes, building materials, drilling techniques, pharmaceuticals, and foodstuffs. New frontiers, including environmentally friendly cellulose fiber technologies, bacterial cellulose biomaterials, and in-vitro syntheses of cellulose are highlighted together with future aims, strategies, and perspectives of cellulose research and its applications.

Cellulose: Fascinating Biopolymer and Sustainable Raw Material

The Huisgen 1,3-dipolar cycloaddition reaction of organic azides and alkynes has gained considerable attention in recent years due to the introduction in 2001 of Cu(1) catalysis by Tornoe and Meldal, leading to a major improvement in both rate and regioselectivity of the reaction, as realized independently by the Meldal and the Sharpless laboratories. The great success of the Cu(1) catalyzed reaction is rooted in the fact that it is a virtually quantitative, very robust, insensitive, general, and orthogonal ligation reaction, suitable for even biomolecular ligation and in vivo tagging or as a polymerization reaction for synthesis of long linear polymers. The triazole formed is essentially chemically inert to reactive conditions, e.g. oxidation, reduction, and hydrolysis, and has an intermediate polarity with a dipolar moment of ∼5 D. The basis for the unique properties and rate enhancement for triazole formation under Cu(1) catalysis should be found in the high ∆G of the reaction in combination with the low character of polarity of the dipole of the noncatalyzed thermal reaction, which leads to a considerable activation barrier. In order to understand the reaction in detail, it therefore seems important to spend a moment to consider the structural and mechanistic aspects of the catalysis. The reaction is quite insensitive to reaction conditions as long as Cu(1) is present and may be performed in an aqueous or organic environment both in solution and on solid support.

Cu-catalyzed azide-alkyne cycloaddition.

Advanced functional polymer membranes

Adsorption of dyes and heavy metal ions by chitosan composites: A review

Dissolution of cellulose with ionic liquids and its application : a mini-review

Unconventional methods in cellulose functionalization

Dextran, comprising a family of neutral polysaccharides consisting of an α-(1 → 6) linked d-glucose main chain with varying proportions of linkages and branches, depending on the bacteria used, is an interesting starting material for chemical modification reactions for the design of new functional polymers with promising properties. The review summarises recent results on structure characterisation of dextran including some comments on biosynthesis of this important class of biopolymers. Applications of dextran are discussed as well. Chemical modification reactions of dextran are increasingly studied for the structure and hence property design. The review highlights recent progress in esterification of dextran, both inorganic and organic polysaccharide esters, etherification reactions towards ionic and non-ionic ethers, and the huge variety of different conversions mainly developed for the binding of drugs. It summarises recent developments in the application of dextran derivatives with a focus on the chemical structures behind these materials such as prodrugs, bioactivity of inorganic dextran esters, heparin sulfate mimics, hydrogels, nanoparticles and self assembly structures for surface modification.

Functional Polymers Based on Dextran

Rheological properties of cellulose/ionic liquid solutions: from dilute to concentrated states.

Summary: The copper-catalyzed Huisgen reaction as a typical example of click chemistry was realized with the polysaccharide cellulose for the first time The generality, selectivity, and the efficiency of click chemistry perfectly fit the requirements of polysaccharide modification, which is demonstrated by the introduction of triazole-spacer bound functional groups, ie, carboxylic ester, thiophene, and aniline moieties Azide moieties introduced into cellulose via the tosyl derivative were simply transferred with ethynyl compounds under Cu(I) catalysis and mild and easily applicable conditions Hydrolytically stable cellulose derivatives soluble in organic solvents, eg, DMSO or DMF with DS up to 09 are obtained The triazole substituted cellulose derivatives were characterized by elemental analysis, FTIR, 1H NMR, and 13C NMR spectroscopies and show no impurities or substructures resulting from side reactions

6-Azido-6-deoxy cellulose

Click Chemistry with Polysaccharides

CONTENTS APPROACHES FOR THE DISSOLUTION OF CELLULOSE 1. Cellulose Solvents - Remarkable History, Bright Future TIM LIEBERT 2. Design of Polar Ionic Liquids To Solubilize Cellulose without Heating YUKINOBU FUKAYA, KENSAKU HAYASHI, SEUNG SEOB KIM AND HIROYUKI OHNO 3. Advances in Aqueous Cellulose Solvents ANG LUE AND LINA ZHANG 4. Molten Inorganic Salts as Reaction Medium for Cellulose S. FISCHER AND K. THUMMLER 5. Dimethyl Sulfoxide and Ammonium Fluorides - Novel Cellulose Solvents THOMAS HEINZE AND SARAH KOHLER INTERACTION OF SOLVENTS WITH CELLULOSE 6. Hydrogen Bond Acceptor Properties of Ionic Liquids and Their Effect on Cellulose Solubility M. SELLIN, B. ONDRUSCHKA AND A. STARK 7. On the Specific Behaviour of Native Cellulose Fibers upon Dissolution N. LE MOIGNE AND P. NAVARD 8. Side Reactions in the System Cellulose/1-Alkyl-3-methyl-imidazolium Ionic Liquid MICHAEL SCHREMS, GERALD EBNER, FALK LIEBNER, ERNST BECKER, ANTJE POTTHAST AND THOMAS ROSENAU 9. Cellulose Solubility: Dissolution and Analysis of "Problematic" Cellulose Pulps in the Solvent System DMAc/LiCl UTE HENNIGES, SONJA SCHIEHSER, THOMAS ROSENAU AND ANTJE POTTHAST 10. Comparison of Solution-State Properties of Cellulose Dissolved in NaOH/Water and in Ionic Liquid (EMIMAc) T. BUDTOVA, M. EGAL, R. GAVILLON, M. GERICKE, T. HEINZE, T. LIEBERT, C. ROY, K. SCHLUFTER AND P. NAVARD 11. Aspects of the Interaction of Native and Synthetic Polymers with Direct Dissolving Liquids B. KOSAN, K. SCHWIKAL, S. HESSE-ERTELT, A. NECHWATAL, F. HERMANUTZ AND F. MEISTER 12. Effect of Enzymatic Treatment on Solubility of Cellulose in 7.6%NaOH-Water and Ionic Liquid PETER ROSENBERG, TATIANA BUDTOVA, MONIKA ROM AND PEDRO FARDIM MODIFICATIONS OF CELLULOSE USING SOLVENTS 13. Non-Halide Ionic Liquids for Solvation, Extraction, and Processing of Cellulosic Materials MICHAEL HUMMEL, GERHARD LAUS, ALEXANDER SCHWARZLER, GINO BENTIVOGLIO, EGON RUBATSCHER, HOLGER KOPACKA, KLAUS WURST, VOLKER KAHLENBERG, THOMAS GELBRICH, ULRICH J. GRIESSER, THOMAS RODER, HEDDA K. WEBER, HERWIG SCHOTTENBERGER AND HERBERT SIXTA 14. Properties of Cellulose/TiO2 Fibers Processed from Ionic Liquids MIRELA L. MAXIM, NING SUN, RICHARD P. SWATLOSKI, MUSTAFIZUR RAHMAN, ADAM G. HARLAND, ANWARUL HAQUE, SCOTT K. SPEAR, DANIEL T. DALY AND ROBIN D. ROGERS 15. Novel Cellulose Products Prepared by Homogeneous Functionalization of Cellulose in Ionic Liquids SUSANN DORN, MICHAEL SCHOBITZ, KERSTIN SCHLUFTER AND THOMAS HEINZE 16. Dissolution of Cellulose in Ionic Liquids and Its Application for Cellulose Processing and Modification LIU CHUANFU, SUN RUNCANG, ZHANG AIPING AND LI WEIYING 17. Imidazolium Based Ionic Liquids as Solvents for Cellulose Chemistry JURGEN VITZ, TINA ERDMENGER AND ULRICH S. SCHUBERT 18. Structure-Property Relationship of Cellulose Ethers - Influence of the Synthetic Pathway on Cyanoethylation B. VOLKERT, W. WAGENKNECHT AND M. MAI 19. Opportunities with Wood Dissolved in Ionic Liquids HAIBO XIE, ILKKA KILPELAINEN, ALISTAIR KING, TIMO LESKINEN, PAULA JARVI AND DIMITRIS S. ARGYROPOULOS 20. Advances in Cellulose Solvent- and Organic Solvent-Based Lignocellulose Fractionation (COSLIF) Y.-H. PERCIVAL ZHANG, ZHIGUANG ZHU, JOE ROLLIN AND NOPPADON SATHITSUKSANOH INDEXES AUTHOR INDEX SUBJECT INDEX

Tim Liebert

Papers

Unconventional methods in cellulose functionalization

Functional Polymers Based on Dextran

Rheological properties of cellulose/ionic liquid solutions: from dilute to concentrated states.

Click Chemistry with Polysaccharides

Cellulose solvents : for analysis, shaping and chemical modification